A patient-derived stem cell model of hereditary spastic paraplegia with SPAST mutations.

There was an error published in Dis. Model. Mech. 6, 489-502.

Due to a technical error with the image analysis software, the published speed unit of peroxisome movement is incorrect. The stated peroxisome speed unit (µm/second) should be changed to µm/2 seconds in two different places in the paper: (1) twice in the Results section ‘Dynamics of peroxisome movement’, and (2) the x-axis of Fig. 5 (the legend remains the same). The correct text and figure is shown below. This change does not alter any conclusions of the paper, which was a comparison of cells from patients and controls.

(1) The mean peroxisome speed in patient cells was 93% slower than in control cells (control, 0.172±0.001 μm/2 seconds; patient, 0.160±0.001 μm/2 seconds; t=9.19, d.f.= 24,398, P<0.0001).

(2) Fig. 5. Peroxisome speeds were slower in patient and control cells. Frequency distributions of peroxisomes in different speed classes are shown for control cells (open bars; n=7 individuals, 10 cells per individual) and patient cells (filled bars; n=6 individuals, 10 cells per individual). Peroxisome speeds were quantified every 2 seconds for 2 minutes and grouped in speed classes expressed as the percentage of peroxisomes in each speed class as a percentage of the total number of peroxisomes for each group (control cells, n=13,871 peroxisomes; patient cells, 10,529 peroxisomes).

The authors apologise to the readers for any confusion that this error might have caused.